How to use testimonials (text, image, video) to increase conversion rates

Video Testimonials:
eDiets does a great job implementing a video testimonial AND focusing the user on the form. I love it! This one above is my favorite example of a landing page that makes effective use of a video & testimonial. I'd love to find out how much this video boosted form completion rates. Does anyone know? Check more examples after the jump.

Video Use in Email Capture, Sign up, Download Landing Page Designs

I've noticed a good number of landing pages with embedded video clips.

The videos can be categorized into 2 types:

1. Hard Selling:
   Directly selling the product - asking the user to use the service, etc
2. Soft Selling:
   Passively provides background information or instructions to urge the user to make a favorable action on the site (ie. click or fill out a form)

Auto-play:
Hard Sell videos tend to play automatically, while Soft sell videos require user action to play.

Placement:
Hard Sell videos tend to be featured above the fold, while Soft sell video placement varies.

Video Hosts:
Viddler, Youtube, embedded flash

Here are some examples of email capture, sign up, download landing pages that have embedded video for your inspiration needs: